How Many Ounces Can You Bring on a Plane? 3.4 oz Carry-On Limit, Size Chart & Checked Bags (2026)

Packing Rules · Updated 2026 · 8 min read

TSA officer at San Francisco International Terminal G explaining to a traveller that his 4.2 oz toothpaste tube is over the 3.4 oz limit, beside a card reading 3.4 oz or 100 ml maximum — 3.4 oz is the most one container can hold. A 4.2 oz tube is over, even when it is nearly empty.

In a carry-on, the limit is 3.4 ounces (100 ml) per container, and every container has to fit in one quart-size bag. That is the answer to “how many ounces can you bring on a plane”. In a checked bag there is no 3.4 oz rule, but toiletries and aerosols are capped at 500 ml (17 fl oz) per container and 2 L (70 oz) in total.

Not sure whether your bottle is under the line? Type its size below.

3.4 oz

carry-on limit per container (100 ml)

quart-size bag per passenger

17 oz

toiletry cap per container, checked bag (500 ml)

70 oz

toiletry cap in total, checked bag (2 L)

📏 Check your size

Size on the label

Unit

Which bag?

Use the size printed on the container. If the label shows both ounces and millilitres, use the millilitres.

📊 Ounces to ml: size chart

The sizes people actually find on labels, with the carry-on and checked-bag answer for each. One US fluid ounce is 29.57 ml, so 100 ml is 3.38 fl oz, and TSA rounds the limit to 3.4 oz.

Size on label	Millilitres	Carry-on bag	Checked bag
1 oz	30 ml	Yes	YesThe classic travel bottle.
1.7 oz	50 ml	Yes	YesCommon mini perfume and toner size.
2 oz	59 ml	Yes	Yes
3 oz	89 ml	Yes	Yes
3.4 oz	100 ml	Yes, the limit	YesTSA's maximum. 3.4 fl oz is 100.6 ml, so TSA names it as the cut-off.
3.5 oz	104 ml	❌ Over	YesA common label size. It is over 3.4 oz, so TSA rules say no.
4 oz	118 ml	❌ Over	YesMany toothpaste tubes and sunscreens. Same rule: the printed size counts.
5 oz	148 ml	❌ Over	Yes
6 oz	177 ml	❌ Over	Yes
8 oz	237 ml	❌ Over	YesA cup of liquid.
12 oz	355 ml	❌ Over	YesA can of soda.
16 oz	473 ml	❌ Over	YesA pint.
16.9 oz	500 ml	❌ Over	YesA small water bottle. Right at the toiletry cap.
17 to 18 oz	503 to 532 ml	❌ Over	⚠️ LimitToiletries and aerosols must be 500 ml (17 fl oz) or less per container.
33.8 oz	1 L	❌ Over	⚠️ Toiletries: noFine for drinks and food. Not allowed for toiletries or aerosols (cap 500 ml).

The checked-bag column is for toiletries and aerosols, the products the 500 ml cap applies to. Alcohol, fuel and pressurised cans have their own rules; see aerosols on a plane.

Shop clerk at Seattle-Tacoma airport pointing a customer to a shelf of travel-size bottles marked 1 oz, 2 oz and 3.4 oz — Travel-size shelves are built around the limit: 1 oz, 2 oz and 3.4 oz bottles.

🧴 What counts as one 3.4 oz item

The limit is written per container: 3.4 ounces (100 milliliters) or less per item. Two things follow from that.

The printed size counts, not what is left. A half-empty 6 oz bottle is still a 6 oz bottle.

There is no total-ounces limit in the carry-on. You can bring as many 3.4 oz containers as fit in one quart-size bag. How many that is depends on their shape; TSA does not publish a number.

Tubes, jars and sprays all count. If you can pour, spray, squeeze, spread or smear it, it is a liquid. Search 93 products in Is It a Liquid? The full TSA list.

🧳 Checked bags: the ounce limits

Full-size bottles are fine in a checked bag. The one cap TSA quotes on its item pages for perfume, nail polish, deodorant, sunscreen and hand sanitizer is the FAA’s: 2 kg or 2 L (70 oz) in total per person, and no single container above 0.5 kg or 500 ml (about 17 fl oz).

⚠️

Drinks and food are not covered by that cap, but alcohol between 24% and 70% is limited to 5 L in unopened retail packaging, and airlines have their own weight limits. See the duty-free alcohol allowance by country.

Items that can go over 3.4 oz in a carry-on

Three groups are allowed above 3.4 oz. You must declare them at the start of screening, and they may get extra checks.

💊

Medically necessary liquids, in reasonable quantities for your trip. See the liquid medication exemption.

🍼

Baby formula, breast milk and baby food. See baby food and formula on a plane.

🛍️

Duty-free liquids bought abroad on a connecting flight to the US, in a sealed tamper-evident bag with the receipt. See is a duty-free bag an extra carry-on.

TSA officer at Orlando International talking with an older traveller about an 8 oz bottle of liquid medication that he is declaring — Medically necessary liquids can go over 3.4 oz if you declare them at the start of screening.

🌍 Millilitres, and flights outside the US

The same limit is written 100 ml in most other countries. This page is TSA’s rule for US airports; details differ by country, and some airports with newer scanners have changed them. For the metric version, see how many ml you can take on a plane.

Before you fly — checklist

Read the size on every bottle. 3.4 oz or 100 ml is the most one container can hold.

3.5 oz and 4 oz bottles are over the limit, even if they are nearly empty.

Everything under the limit goes together in one quart-size bag.

Bigger bottles go in the checked bag, up to 500 ml (17 fl oz) per toiletry or aerosol container and 2 L (70 oz) in total.

Medicine, baby milk and baby food can go over 3.4 oz. Declare them first.

Empty drink bottles before security and refill after.

The final decision rests with the TSA officer at the checkpoint, and rules at airports outside the US differ. Confirm current requirements with TSA before you travel. Updated 2026.

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Packing it in a checked bag? See how much liquid you can put in a checked bag: what is allowed, limited or banned.

🔗 Useful sources

TSA — Liquids, aerosols and gels rule TSA — What can I bring: full item list FAA — PackSafe: items you can and cannot pack UK Government — Hand luggage restrictions